When you open a library, EagleFiler checks that all the files and notes are
present. The Verify command does this, and it additionally checks that their
contents are what EagleFiler was expecting. To verify the entire library,
select the Records source and choose Verify. You can also verify
individual files or folders.

Detecting File Corruption

Verification can help you detect file corruption before it becomes a serious
problem. For example, if there is damage to your disk and a file becomes
corrupt, you’ll learn of the problem as soon as you use the Verify
command. Without Verify, you would only learn of the problem when
you tried to access the file (perhaps a long time in the future), and
perhaps not even then, because the corruption might not be readily
apparent. Because you learn about the damage early, you can restore a
correct version of the file from a backup, rather than filling your
future backups with damaged copies of the file.

How Verification Works

In order to detect when files have changed, EagleFiler stores a checksum
of each file. If EagleFiler reads a file and calculates the same
checksum that it got before, it knows that the file has not changed.
Thus, if the file was in good condition before, it is still in good
condition. If EagleFiler calculates a different checksum, that means
that the file’s contents are different.

Sometimes, the checksum should be different. For example, when you
edit a file, you intentionally change its contents, resulting in a
different checksum. When you edit a file within EagleFiler, EagleFiler
automatically updates its stored checksum to match the file’s new
contents. Thus, if you only edit files using EagleFiler, the checksums
will always be in sync with the files’ contents, and any checksum that
doesn’t match means that the file is damaged.

EagleFiler also allows you edit files using other applications. For
example, you can double-click a Microsoft Word document to open it in
Word, make some changes, and choose File ‣ Save. In this case, the
file has changed, but there is no way for EagleFiler to know that this
is because of what you did in Word. The changes could have been due to
damage. Thus, if you edit a file outside of EagleFiler, you must use the
Update Checksum command to tell EagleFiler that the file’s current contents
are correct. EagleFiler will then update its stored checksum to match.

Using the Verify Command

Verify is a specialized feature for people who want extra data
integrity protection. If you don’t need this, or if you frequently edit
files outside of EagleFiler and don’t want to have to Update
Checksum, then you can simply ignore the Verify command.
EagleFiler will then behave like a normal Mac application: it won’t
complain about files being different than it expected, but neither will
it detect when they are damaged.

A verification can fail with two different types of errors:

Missing File

This means that you had a file in your library, but it is no longer where
EagleFiler expects to find it. Probably the file (or a containing folder)
was renamed, moved, or deleted using an application other than EagleFiler.
(As described in the Library Folders section, you should not do this.)

The Errors window shows the expected name of the file, and you can click
Reveal to show its expected folder in the Finder or Reveal in
Library to show its expected folder in EagleFiler.

If you can find the file in the Finder (or in a backup), use the Finder to
move back to the expected folder. Then EagleFiler will be able to find it
again.

If you cannot find the file, you click the Trash button to delete it in
EagleFiler and then empty the trash so that EagleFiler stops looking for it.

Bad Checksum

This means that the file’s contents no longer match what EagleFiler was
expecting. If you have modified the file outside of EagleFiler, this is
normal and you can click Update Checksum to tell EagleFiler that the
file is OK. Otherwise, the file is probably damaged, and you should try to
restore it from a backup. Use the Finder to move the correct file into
place, replacing the one with the bad checksum.

To quickly delete a large number of verification errors, choose Edit ‣ Select
All and then press the Delete key.

Repairing File Ownership and Permissions

In addition to detecting damaged file content, the Verify command can
optionally fix file metadata problems. See the FixOwnershipWhenVerifying and
FixPermissionsWhenVerifying options in the esoteric preferences.